Display case door assembly with tempered glass vacuum panel

ABSTRACT

A display case door assembly for a temperature-controlled storage device includes an opening into the temperature-controlled storage device and a vacuum panel mounted within the opening. The vacuum panel includes a first vacuum pane of tempered glass, a second vacuum pane of tempered glass, and an evacuated gap between the first and second vacuum panes. The evacuated gap has a predetermined thickness within which a vacuum is drawn, thereby providing a thermal insulation effect for the vacuum panel. The vacuum panel further includes a plurality of spacers disposed within the evacuated gap and configured to maintain the predetermined thickness of the evacuated gap when the vacuum is drawn therein.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/563,760 filed Dec. 8, 2014, which claims the benefit of andpriority to U.S. Provisional Patent Application No. 61/938,555 filedFeb. 11, 2014. The entireties of both U.S. patent application Ser. No.14/563,760 and Provisional Patent Application No. 61/938,555 areincorporated by reference herein.

BACKGROUND

This section is intended to provide a background or context to theinvention recited in the claims. The description herein may includeconcepts that could be pursued, but are not necessarily ones that havebeen previously conceived or pursued. Therefore, unless otherwiseindicated herein, what is described in this section is not prior art tothe present invention and is not admitted to be prior art by inclusionin this section.

Temperature-controlled storage devices (e.g., a refrigerator, freezer,refrigerated merchandiser, display case, etc.) are used in a widevariety of commercial, institutional, and residential applications forstoring and/or displaying refrigerated or frozen objects. Manytemperature-controlled storage devices have a display case door (e.g., adoor with an insulated glass panel) through which objects within thetemperature-controlled storage device can be viewed.

Conventional insulated glass panels typically include multiple parallelpanes with a layer of gas between the panes. The gas is generally air ora noble gas (e.g., Argon, Krypton, etc.) which functions as a thermalinsulator to reduce heat transfer through the panel. In conventionalinsulated glass panels, the pressure of the air or gas between the panesis equal or substantially equal to atmospheric pressure. Reducing thepressure of the air or gas between the panes would cause atmosphericpressure to apply a large force (e.g., thousands of pounds of force) tothe surface of the panel. Such a force is likely to bend or break aninsulated glass panel, especially if the panel is relatively thin.

Vacuum insulated glass is a type of insulated glass panel which uses anevacuated space or gap between parallel panes of glass as an insulatinglayer. The manufacture of vacuum insulated glass typically involvessealing parallel panes of glass to each other at their edges (e.g.,using glass solder) and drawing a vacuum in a thin gap between theparallel panes. Such a manufacturing process requires the panes of glassto be held at a high temperature while the edge seal is formed in orderto ensure proper bonding.

Conventional vacuum insulated glass panels use panes of non-temperedglass. Non-tempered glass typically has an improved flatness relative totempered glass, which allows the gap between panes to have asubstantially uniform thickness. However, non-tempered glass istypically more fragile than tempered glass and fractures into largershards when broken. Using tempered glass in a vacuum insulated glasspanel could have significant durability and safety advantages. However,the typical manufacturing process used to create vacuum insulated glasspanels prevents the use of tempered glass because the high temperaturesused to form the edge seal removes any tempering from the glass. Forthese reasons, a vacuum insulated glass panel constructed from temperedglass has not been successfully implemented.

SUMMARY

One implementation of the present disclosure is a display case doorassembly for a temperature-controlled storage device. The display casedoor assembly includes an opening into the temperature-controlledstorage device and a vacuum panel mounted within the opening. The vacuumpanel includes a first vacuum pane of tempered glass, a second vacuumpane of tempered glass, and an evacuated gap between the first andsecond vacuum panes. The evacuated gap has a predetermined thicknesswithin which a vacuum is drawn, thereby providing a thermal insulationeffect for the vacuum panel. The vacuum panel further includes aplurality of spacers disposed within the evacuated gap and configured tomaintain the predetermined thickness of the evacuated gap when thevacuum is drawn therein.

In some embodiments, the display case door assembly includes a perimeterseal bonding a perimeter of the first vacuum pane to a perimeter of thesecond vacuum pane and providing a hermetic seal within the evacuatedgap. The perimeter seal may have a melting temperature below a glasstransition temperature of the tempered glass. The perimeter seal may bebonded to the perimeter of the first vacuum pane and the perimeter ofthe second vacuum pane by heating the perimeter seal to the meltingtemperature without detempering the tempered glass. In some embodiments,the first vacuum panel and the second vacuum panel are bonded togetherusing an ultrasonic welding process which forms a hermetic seal betweenthe first vacuum panel and the second vacuum panel without detemperingthe tempered glass.

In some embodiments, the predetermined thickness of the evacuated gap isless than 1 millimeter. In some embodiments, the predetermined thicknessof the evacuated gap is approximately 0.2 millimeters. In someembodiments, the plurality of spacers are arranged in a grid andseparated from each other by a distance approximately 250 times thepredetermined thickness of the evacuated gap. In some embodiments, theplurality of spacers are arranged in a grid and separated from eachother by a distance of approximately 50 millimeters.

In some embodiments, at least one of the first vacuum pane and thesecond vacuum pane is made of a low emissivity material configured toreduce radiation heat transfer through the vacuum panel. In someembodiments, the display case door assembly includes a protective layerlaminated to an outside surface of the vacuum panel and configured toprevent the vacuum panel from breaking into a plurality of uncontainedshards. In some embodiments, the display case door assembly includes afilm or coating laminated to a surface of the vacuum panel. The film orcoating may include at least one of an anti-condensate layer, anultraviolet inhibiting layer, and a low emissivity layer.

Another implementation of the present disclosure is a vacuum panel for atemperature-controlled storage device. The vacuum panel includes a firstvacuum pane of tempered glass, a second vacuum pane of tempered glass,and an evacuated gap between the first and second vacuum panes. Theevacuated gap has a predetermined thickness within which a vacuum isdrawn, thereby providing a thermal insulation effect for the vacuumpanel. The vacuum panel further includes a plurality of spacers disposedwithin the evacuated gap and configured to maintain the predeterminedthickness of the evacuated gap when the vacuum is drawn therein.

In some embodiments, the vacuum panel includes a perimeter seal bondinga perimeter of the first vacuum pane to a perimeter of the second vacuumpane and providing a hermetic seal within the evacuated gap. Theperimeter seal may have a melting temperature below a glass transitiontemperature of the tempered glass. The perimeter seal may be bonded tothe perimeter of the first vacuum pane and the perimeter of the secondvacuum pane by heating the perimeter seal to the melting temperaturewithout detempering the tempered glass. In some embodiments, the firstvacuum panel and the second vacuum panel are bonded together using anultrasonic welding process which forms a hermetic seal between the firstvacuum panel and the second vacuum panel without detempering thetempered glass.

In some embodiments, the predetermined thickness of the evacuated gap isless than 0.5 millimeters. In some embodiments, at least one of thefirst vacuum pane and the second vacuum pane is made of a low emissivitymaterial configured to reduce radiation heat transfer through the vacuumpanel. In some embodiments, the plurality of spacers are arranged in agrid and separated from each other by a distance approximately 250 timesthe predetermined thickness of the evacuated gap. In some embodiments,the plurality of spacers are arranged in a grid and separated from eachother by a distance of approximately 50 millimeters.

Another implementation of the present disclosure is thermally-insulatedvacuum panel. The vacuum panel includes a first vacuum pane of temperedglass, a second vacuum pane of tempered glass, an evacuated gap betweenthe first and second vacuum panes providing a thermal insulation effectfor the vacuum panel, and a perimeter seal bonding a perimeter of thefirst vacuum pane to a perimeter of the second vacuum pane. Theperimeter seal provides a hermetic seal within the evacuated gap and hasa melting temperature below a glass transition temperature of thetempered glass. The perimeter seal is bonded to the perimeter of thefirst vacuum pane and the perimeter of the second vacuum pane by heatingthe perimeter seal to the melting temperature without detempering thetempered glass.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a display case door assembly including adoor frame and four display case doors coupled to the door frame via arail assembly, each door having a transparent vacuum panel, according toan exemplary embodiment.

FIG. 2 is a front elevation view of the display case door assembly ofFIG. 1, according to an exemplary embodiment.

FIG. 3 is a cross-sectional plan view of the display case door assemblyof FIG. 1 taken along line 3-3 of FIG. 2, according to an exemplaryembodiment.

FIG. 4 is a detail taken from FIG. 2 as indicated, according to anexemplary embodiment.

FIG. 5 is a detail taken from FIG. 2 as indicated, according to anexemplary embodiment.

FIG. 6 is a detail taken from FIG. 2 as indicated, according to anexemplary embodiment.

FIG. 7A is an exploded view of the vacuum panel shown in FIG. 1,according to an exemplary embodiment.

FIG. 7B is a front elevation view of the vacuum panel shown in FIG. 7A,according to an exemplary embodiment.

FIG. 7C is a detail view of a portion of the vacuum panel shown in FIG.7A, according to an exemplary embodiment.

FIG. 7D is a side cross-sectional view of the vacuum panel shown in FIG.7A, according to an exemplary embodiment.

FIG. 7E is a top view of a vacuum tube which may be used to draw avacuum within the vacuum panel, according to an exemplary embodiment.

FIG. 7F is a front cross-sectional view of the vacuum tube shown in FIG.7E, according to an exemplary embodiment.

FIG. 7G is a perspective view of the vacuum tube shown in FIG. 7E,according to an exemplary embodiment.

FIG. 7H is a top view of a cap which may be used to cover a vacuum portin the vacuum panel, according to an exemplary embodiment.

FIG. 7I is a perspective view of the cap shown in FIG. 7H, according toan exemplary embodiment.

FIG. 7J is a front view of the cap shown in FIG. 7H, according to anexemplary embodiment.

FIG. 7K is a side cross-sectional view of the cap shown in FIG. 7H,according to an exemplary embodiment.

FIG. 7L is a front elevation view of one of the vacuum panes which maybe used to form the vacuum panel shown in FIG. 1, according to anexemplary embodiment.

FIG. 7M is a detail view of a portion of the vacuum pane shown in FIG.7L, according to an exemplary embodiment.

FIG. 7N is a flow diagram illustrating a manufacturing process which maybe used to form the vacuum panel shown in FIG. 1, according to anexemplary embodiment.

FIG. 8A is a perspective view of the transparent glass unit of FIG. 1,according to an exemplary embodiment.

FIG. 8B is a cross-sectional view of the transparent glass unit shown inFIG. 8A, according to an exemplary embodiment.

FIG. 9 is a perspective view of the transparent glass unit with edgeguards thereon, according to an exemplary embodiment.

FIG. 10 is a cross-sectional plan view of the rail of the assembly ofFIG. 1, according to an exemplary embodiment.

FIG. 11 is a cross-sectional perspective view of the rail of theassembly of FIG. 1, according to an exemplary embodiment.

FIG. 12 a is a cross sectional perspective view of the rail of theassembly of FIG. 1 with an access cover removed from an access opening,according to an exemplary embodiment.

FIG. 13 is a partial interior perspective view of the assembly of FIG.1, showing electrical hinge pins and doors, according to an exemplaryembodiment.

FIG. 14 is a perspective view of a gravity hinge for use with thedisplay case door assembly of FIG. 1, according to an exemplaryembodiment.

FIG. 15 is a partial interior perspective view of the assembly of FIG. 1showing the gravity hinge of FIG. 14 exploded from the door and rail,according to an exemplary embodiment.

FIG. 16 is a perspective view of a lower portion of the gravity hinge ofFIG. 14 mounted in the door frame of FIG. 1, according to an exemplaryembodiment.

FIG. 17 is a bottom perspective view of the gravity hinge of FIG. 14showing an upper portion of the gravity hinge in an open position,according to an exemplary embodiment.

FIG. 18 is a perspective view drawing of two electrical hinge pins foruse with the display case door assembly of FIG. 1, showing one of thehinge pins exploded away from a female connector, according to anexemplary embodiment.

FIG. 19 is a perspective view of another gravity hinge for use with thedisplay case door assembly of FIG. 1, according to another exemplaryembodiment.

FIG. 20 is a top exploded perspective view of the gravity hinge of FIG.19, according to an exemplary embodiment.

FIG. 21 is a bottom exploded perspective view of the gravity hinge ofFIG. 19, according to an exemplary embodiment.

DETAILED DESCRIPTION Overview

Referring generally to the FIGURES, a display case door assembly with avacuum panel is shown, according to an exemplary embodiment. The displaycase door assembly described herein may be used as a door assembly for arefrigerator, freezer, refrigerated merchandiser, or other display casein a wide variety of commercial, institutional, and residentialapplications. For example, the display case door assembly may be used aspart of a temperature-controlled storage device in a supermarket orother similar facility and may include one or more transparent panels orpanes (e.g., insulated glass panels) through which objects within thetemperature-controlled storage device can be viewed.

The display case door assembly described herein includes a vacuum panel.The vacuum panel may include multiple parallel vacuum panes separated bya small gap (e.g., less than 1 mm, as small as 0.2 mm, etc.). In someembodiments, the gap between the vacuum panes is approximately 0.2 mm.The gap is evacuated to produce a vacuum between the vacuum panes.Advantageously, the vacuum provides a high thermal insulation effect ina relatively small space. In some embodiments, one or more of the panesis made of low emissivity glass to reduce radiation heat transferthrough the vacuum panel.

The vacuum panel may include spacers in the evacuated gap to maintainthe separation between panes when the gap is evacuated. The spacersprevent external pressure (e.g., atmospheric pressure) from causing thevacuum panes to flex inward when a vacuum is drawn between the panes. Insome embodiments, the spacers include a plurality of support pillarsbetween the vacuum panes. The support pillars may be arranged in a grid(e.g., approximately 50 mm apart) and configured to provide internalsupport for the vacuum panel to counter the pressure differential causedby the evacuated gap.

In some embodiments, one or more of the vacuum panes are made oftempered glass. Advantageously, using tempered glass improves thedurability of the vacuum panes relative to non-tempered glass. Sincetempered glass is stronger and can withstand more pressure thannon-tempered glass without incurring damage, the distance between thespacers can be increased relative to conventional vacuum glass panelsthat use non-tempered glass. In some embodiments, distance betweenspacers is approximately 50 mm or 2 inches. Such a distance betweenspacers would not be feasible for non-tempered glass because it resultsin less spacers, thereby distributing the compressive force among lessspacers and increasing the point forces exerted by spacers on the vacuumpanes. If the vacuum panes were made of non-tempered glass, the forcesexerted by the spacers could cause damage to the vacuum panes. However,the use of tempered glass allows the spacers to be separated by agreater distance without causing damage to the vacuum panes.

The vacuum panel may include a perimeter seal. The perimeter seal may besolder glass or another sealing material configured to bond the vacuumpanes along a perimeter thereof and to provide an airtight (i.e.,hermetic) seal within the evacuated gap. In some embodiments, theperimeter seal is made of an inorganic material capable of providing ahermetic seal within the evacuated gap. In some embodiments, theperimeter seal is made of an alloy material specifically formulated forjoining glass, silicon, and other types of silicates. For example, theperimeter seal may be a metallic alloy or an active solder whichincludes tin, silver, and titanium. In some embodiments, the perimeterseal is formed using the “S-BOND® 220M” alloy manufactured by S-BondTechnologies, LLC.

In some embodiments, the perimeter seal is a low-temperature solder orother sealing material that has a melting range significantly lower thanthe glass transition temperature of the vacuum panes. The relativelylower melting temperature of the perimeter seal allows the perimeterseal to melt and bond to the vacuum panes without heating any portion ofthe vacuum panes to a temperature that would remove the temper from theglass. In some embodiments, the vacuum panes are bonded together usingan ultrasonic welding process. The ultrasonic welding process may becharacterized by temperatures well below the glass transitiontemperature of the vacuum panes. Advantageously, these features allowthe vacuum panes to be made of tempered glass and to retain their temperthroughout the manufacturing/bonding process. This advantage allows thevacuum panel to include multiple parallel panes of tempered glass bondedtogether along their perimeter to form a hermetic seal around theevacuated gap.

The vacuum panel described herein provides a thermopane unit thatappears as a single pane of glass due to the minimal separation betweenpanes. The separation between panes of glass is minimized by providingan evacuated layer (e.g., a vacuum layer) which creates a thermobreakhaving a high thermal resistance. The thickness of the evacuated layercan be precisely controlled by providing spacers to maintain theseparation between panes. A coating or laminate layer can be used tokeep the unit intact if breakage occurs. In a preferred embodiment,coating or layer can also function as an anti-condensate coating and/orUV inhibitor.

Before discussing further details of the display case door and/or thecomponents thereof, it should be noted that references to “front,”“back,” “rear,” “upward,” “downward,” “inner,” “outer,” “right,” and“left” in this description are merely used to identify the variouselements as they are oriented in the FIGURES. These terms are not meantto limit the element which they describe, as the various elements may beoriented differently in various applications.

Display Case Door Assembly

Referring now to FIGS. 1-6, a display case door assembly 10 is shown,according to an exemplary embodiment. Display case door assembly 10 maybe used in conjunction with a temperature-controlled storage device(e.g., a refrigerator, a freezer, a warmer, a heater, etc.) for storingand/or displaying refrigerated or frozen goods. For example, displaycase door assembly 10 may be implemented as part of a refrigerateddisplay case in a supermarket, warehouse store, or other similarfacility.

Display case door assembly 10 is shown to include a plurality of displaycase doors 12 mounted in a door frame 14. Each display case door 12includes a vacuum panel 20. In some embodiments, vacuum panel 20 ishingedly connected to frame 14 via a rail 18. In various otherembodiments, vacuum panel 20 may be implemented as part of a slidingdoor or window, a rotary door, a swing sliding door, a fixed-positionwindow or panel, or otherwise positioned within a frame or opening.Vacuum panel 20 may be configured to move relative to the frame oropening (e.g., rotating via hinges as shown in FIG. 1, sliding along atrack, etc.) or may be fixed within the frame or opening. In variousimplementations, vacuum panel 20 may be used as part of a door assemblyconfigured to provide a thermal insulation effect (e.g., for arefrigerated display case) or otherwise used as any type of transparentor substantially transparent panel that provides a thermal insulationeffect (e.g., a sliding or hinged window, a fixed-position window, arevolving or sliding door, a hinged door, etc.).

In some embodiments, frame 14 can be omitted to provide a framelessdisplay case door assembly 10. For example, vacuum panel 20 can bemounted within the opening into the temperature-controlled storagedevice via hinges that directly attach to vacuum panel 20 withoutrequiring an intermediate frame to support and/or contain vacuum panel20. Advantageously, omitting frame 14 enhances the minimalisticappearance of display case door assembly 10 and supplements theaesthetics provided by vacuum panel 20, which appears as a single paneof glass.

In some embodiments, vacuum panel 20 includes one or more panes oftransparent or substantially transparent glass (e.g., insulated glass,non-tempered glass, tempered glass, etc.), plastics, or othertransparent or substantially transparent materials. As such, vacuumpanel 20 may be referred to as a transparent unit. In some embodiments,vacuum panel 20 includes multiple layers of transparent panes (i.e.,multiple panes per door 12). For example, vacuum panel 20 may be amulti-pane unit having a first vacuum pane 21 and a second vacuum pane23. Vacuum panes 21 and 23 may be separated by a small gap 25 which canbe evacuated to draw a vacuum between panes 21 and 23.

Display case door 12 is shown to include edge guards 22. In someembodiments, edge guards 22 are transparent moldings. Edge guards 22 maybe adhered to the top edge, bottom edge, and non-hinge side edge ofvacuum panel 20. Silicon or the like may be used for bonding edge guards22 to the edges of vacuum panel 20. Edge guards 22 provide a sealingfeature for display case door 12. For example, as shown in FIG. 5, theedge guard 22 on the non-hinged edge of vacuum panel 20 (i.e., the edgeopposite the hinged edge) may include a wiper 22 a that cooperates witha wiper 22 a on another door 12 to seal the display case when doors 12are closed. In some embodiments, edge guards 22 can be omitted.

In some embodiments, display case door 12 includes a handle 16. Handle16 may be used to open, close, lock, unlock, seal, unseal, or otherwiseoperate display case door 12. Handle 16 may be made from extrudedaluminum tubes that are cut to a specified dimension and bonded to afront surface of display case door 12. However, this is not a limitationon the present invention and other handle configurations can be used.

Display case door 12 may include any of a variety of structures orfeatures for attaching display case door 12 to frame 14. For example,display case door 12 may include a structure for housing wiring, amullion 11, one or more gaskets 13, and/or other associated brackets andcomponents typically included in refrigerated display cases. Detaileddescriptions of such components are provided in U.S. Pat. Nos.6,606,832, and 6,606,833, which are incorporated by reference herein intheir entireties.

Vacuum Panel

Referring now to FIGS. 7A-7D, several drawings illustrating vacuum panel20 in greater detail are shown, according to an exemplary embodiment. Inbrief overview, FIG. 7A is an exploded view of vacuum panel 20; FIG. 7Bis a front elevation view of vacuum panel 20; FIG. 7C is a detail viewof the portion of vacuum panel 20 circled in FIG. 7B; and FIG. 7D is aside cross-section view of vacuum panel 20.

Vacuum panel 20 is shown to include a front vacuum pane 21 and a rearvacuum pane 23. Front vacuum pane 21 has an outside surface 26 and aninside surface 27. Outside surface 26 faces toward a consumer standingin front of the display case when door 12 is closed. Inside surface 27faces toward merchandise within the display case when door 12 is closed.Rear vacuum pane 23 has an inside surface 28 and an outside surface 29.Inside surface 28 faces toward a consumer standing in front of thedisplay case when door 12 is closed. Outside surface 29 faces towardmerchandise within the display case when door 12 is closed. When vacuumpanel 20 is assembled, inside surfaces 27 and 28 may be separated fromeach other by the width of gap 25.

In some embodiments, vacuum panel 20 includes spacers 30 positionedbetween vacuum panes 21 and 23. Spacers 30 may be configured to maintainthe separation between panes 21 and 23 when gap 25 is evacuated. Spacers30 may prevent external pressure (e.g., atmospheric pressure) fromcausing panes 21 and 23 to flex inward when a vacuum is drawn in gap 25.In some embodiments, spacers 30 include a plurality of support pillarsextending between panes 21 and 23 (i.e., between surfaces 27 and 28).The support pillars may be configured to provide internal compressionsupport for vacuum panel 20 to counter the pressure differential betweenatmospheric pressure outside panes 21 and 23 and the vacuum within gap25 between panes 21 and 23. Spacers 30 may be arranged in a grid (e.g.,approximately 50 mm apart) between panes 21 and 23. In some embodiments,spacers 30 are ceramic spacers. Spacers 30 can be applied using aprinting process or silkscreen process (described in greater detailbelow) to reduce the time and effort required to properly positionspacers 30. For example, one swipe of a silkscreen or an automatedprinting process can place an entire grid of spacers 30 in properlocations without requiring a user to manually place spacers 30.

In some embodiments, front vacuum pane 21 and rear vacuum pane 23 aremade of tempered glass. Advantageously, using tempered glass improvesthe durability of vacuum panes 21 and 23 relative to non-tempered glass.Using tempered glass also improves the safety of vacuum panel 20 bycausing vacuum panes 21 and 23 to fracture into many small pieces in theevent that breakage occurs. Since tempered glass is stronger and canwithstand more pressure than non-tempered glass without incurringdamage, the distance between spacers 30 can be increased relative toconventional vacuum glass panels that use non-tempered glass. Forexample, a vacuum glass panel manufactured from non-tempered glass mayrequire a relatively small distance between spacers 30 (e.g., 20 mm orless) in order to distribute the compressive force among more spacers 30and to reduce the point forces exerted by spacers 30 on vacuum panes 21and 23.

Advantageously, using tempered glass for vacuum panes 21 and 23 allowsspacers 30 to be separated by a greater distance d, as shown in FIG. 7C.In some embodiments, distance d is between 20 mm and 80 mm. In someembodiments, distance d is between 40 mm and 60 mm. In some embodiments,distance d is approximately 50 mm or 2 inches. Such a distance betweenspacers 30 would not be feasible for non-tempered glass because itresults in less spacers 30, thereby distributing the compressive forceamong less spacers 30 and increasing the point forces exerted by spacers30 on vacuum panes 21 and 23. If vacuum panes 21 and 23 were made ofnon-tempered glass, the forces exerted by spacers 30 could cause damageto vacuum panes 21 and 23. However, the use of tempered glass allowsspacers 30 to be separated by distance d without causing damage tovacuum panes 21 and 23.

Vacuum panel 20 is shown to include a perimeter seal 32. Perimeter seal32 may be glass solder, ceramic frit, or another sealing materialconfigured to bond panes 21 and 23 along a perimeter thereof and toprovide an airtight (i.e., hermetic) seal within gap 25. Perimeter seal32 can be applied to one or both of vacuum panes 21 and 23 prior toassembly and may extend along an entire perimeter of vacuum panel 20.Perimeter seal 32 may form a closed perimeter (e.g., a rectangle) andmay be bonded to both of vacuum panes 21 and 23. Spacers 30 may becontained within the closed perimeter formed by perimeter seal 32.

Perimeter seal 32 may be made of an inorganic material capable ofproviding a hermetic seal within gap 25. In some embodiments, perimeterseal 32 is made of an alloy material specifically formulated for joiningglass, silicon, and other types of silicates. For example, perimeterseal 32 may be a metallic alloy or an active solder which includes tin,silver, and titanium. In some embodiments, perimeter seal 32 is formedusing the “S-BOND® 220M” alloy manufactured by S-Bond Technologies, LLC.

In some embodiments, perimeter seal 32 is a ceramic frit made from agranulated or powdered ceramic or glass material. The ceramic frit maybe a ceramic composition that has been fused in a fusing oven, quenchedto form a glass, and granulated. The ceramic frit may be applied tovacuum panes 21 and/or 23 in the form of a powdered or granulated solid,paste, slurry, suspension, or other composition. In some embodiments,the ceramic frit is bonded to the perimeter of vacuum panes 21 and 23using a sintering process. The sintering process may involve compactingand forming a solid mass of material by applying heat and/or pressure tothe perimeter of vacuum panes 21 and 23 after a layer of the ceramicfrit has been applied along the perimeter (e.g., between vacuum panes 21and 23). The heat applied may be sufficient to bond the ceramic frit tothe perimeter of vacuum panes 21 and 23 without heating vacuum panes 21and 23 to a temperature that would remove the temper from the glass.

In some embodiments, perimeter seal 32 is a low-temperature solder orother sealing material that has a melting range significantly lower thanthe glass transition temperature of vacuum panes 21 and 23. For example,perimeter seal 32 may have a melting range of approximately 220° C.-280°C., whereas the glass transition temperature of vacuum panes 21 and 23may be approximately 520° C.-600° C. (i.e., the glass transitiontemperature for soda lime glass). The relatively lower meltingtemperature of perimeter seal 32 allows perimeter seal 32 to melt andbond to vacuum panes 21 and 23 without heating any portion of vacuumpanes 21-23 to a temperature that would remove the temper from theglass. Advantageously, this allows vacuum panes 21 and 23 to be made oftempered glass and to retain their temper throughout themanufacturing/bonding process. This advantage allows vacuum panel 20 toinclude multiple parallel panes of tempered glass (i.e., vacuum panes 21and 23) bonded together along their perimeter to form a hermetic sealaround gap 25.

In some embodiments, vacuum panes 21 and 23 are bonded together using anultrasonic welding process. Ultrasonic welding is an industrialtechnique whereby high-frequency ultrasonic acoustic vibrations arelocally applied to workpieces being held together under pressure tocreate a solid-state weld. The main components of an ultrasonic weldingsystem are a high-frequency voltage generator, a converter (i.e., anultrasonic transducer), a booster, and a welding tool called asonotrode. The high-frequency voltage generator converts an inputvoltage into a high frequency voltage, which is transformed by theconverter into mechanical oscillations of the same frequency. Thebooster modifies (i.e., amplifies) the amplitude of vibration based on asignal from a controller. The sonotrode emits the converted energy inthe form of mechanical shear waves into the components being weldedtogether (i.e., vacuum panes 21 and 23). During the welding process, thesonotride may be pressed onto an exterior surface of vacuum pane 21 orvacuum pane 23 by a perpendicular force. In some embodiments, theperpendicular force is within the range of 250 N-350 N.

Advantageously, the ultrasonic welding process may be characterized bytemperatures well below the glass transition temperature of vacuum panes21 and 23. For example, the ultrasonic welding process can be performedto form a hermetic seal between vacuum panes 21 and 23 without exposingany portion of vacuum panes 21 and 23 to a temperature that would removethe temper from the glass. This advantage allows vacuum panes 21 and 23to be made of tempered glass and to retain their temper throughout theultrasonic welding process. The ultrasonic welding can be performed withor without an intermediate adhesive or solder used to bond vacuum panes21 and 23. For example, perimeter seal 32 may be used in someembodiments and omitted in other embodiments. If perimeter seal 32 isused, the ultrasonic welding process may be performed to melt and bondperimeter seal 32 to vacuum panes 21 and 23 at a temperaturesignificantly below the glass transition temperature of vacuum panes 21and 23. If perimeter seal 32 is not used, the ultrasonic welding processmay be performed to bond vacuum panes 21 and 23 directly to each other.

In some embodiments, perimeter seal 32 and spacers 30 are formed using aprinting process (e.g., 2D or 3D printing, ceramic in-glass printing,etc.) or an additive manufacturing process. For example, a printer(e.g., a dot-matrix printer, a ceramic printer, a 3D printer, etc.) canbe used to print a layer of material along the perimeter of vacuum pane21 and/or vacuum pane 23 to form perimeter seal 32. The printer can alsobe used to print columns or dots of material to form a grid of spacers30 at the locations shown in FIGS. 7B-7C. In various embodiments,perimeter seal 32 and spacers 30 may be formed using different materialsor the same material. For example, the printer may be configured toprint a layer of a first material along the perimeter of vacuum panes 21and/or 23 to form perimeter seal 32, and a layer of a second material toform spacers 30 at the locations shown in FIGS. 7B-7C. The differentmaterials/layers may be printed sequentially or concurrently using aprinter that can switch between printing different materials.

In some embodiments, perimeter seal 32 and spacers 30 are formed using aglass printing process. The glass printing process may include using anin-glass printer and/or digital ceramic inks to print perimeter seal 32and/or spacers 30 onto a surface of vacuum pane 21 and/or vacuum pane23. Exemplary in-glass printers and digital ceramic inks may which maybe used to perform the glass printing process may include thosemanufactured by Dip-Tech Digital Printing Technologies Ltd. The glassprinting process may include printing a layer of ceramic ink onto vacuumpane 21 and/or vacuum pane 23, drying the ceramic ink (e.g., using ablower or dryer), placing vacuum panes 21 and 23 in parallel with eachother with the layer of ceramic ink between vacuum panes 21 and 23, andtempering the assembly to fuse the ceramic ink to both vacuum panes 21and 23.

Vacuum panel 20 is shown to include a vacuum port 34. Vacuum port 34 maybe used to remove air from gap 25 after vacuum panel 20 has beenassembled to draw a vacuum within gap 25. In various embodiments, vacuumport 34 may extend through vacuum pane 21 or vacuum pane 23. Vacuum port34 may be formed (e.g., drilled, cut, etc.) prior to tempering vacuumpanes 21 and 23 to avoid damage that could result from forming a vacuumport in tempered glass. After vacuum port 34 is formed, vacuum panes 21and 23 may be tempered. A cap 33 may be used to cover vacuum port 34once the vacuum has been drawn within gap 25. Cap 33 can be adhered tooutside surface 29 or 26 using any of a variety of adhesives or sealingmaterials. In some embodiments, cap 33 is adhered using the samematerial used to form perimeter seal 32.

In some embodiments, vacuum panel 20 includes a getter 31 located withingap 25. Getter 31 may be a reactive material configured to remove smallamounts of gas from gap 25. For example, getter 31 may be configured tocombine chemically with gas molecules within gap 25 or may remove thegas molecules by adsorption. Advantageously, getter 31 helps to form andmaintain the vacuum within gap 25 by removing any gas molecules notremoved via vacuum port 34 or which leak into gap 25 over time. In someembodiments, getter 31 is inserted into gap 25 in a preformed condition.In other embodiments, getter 31 can be printed onto vacuum panel 21 or23 along with perimeter seal 32 and/or spacers 30.

In some embodiments, one or more of surfaces 26-29 have a film orcoating applied thereto. For example, one or more of surfaces 26-29 mayhave an anti-condensate film or coating (e.g., a pyrolitic coating, amylar coating, etc.) which may be used to prevent condensation fromoccurring. In one embodiment, the anti-condensate film or coating isapplied to surface 29. In some embodiments, the film or coating appliedto surface 29 prevents the contamination of merchandise in thetemperature-controlled storage device in the event that vacuum panels 21and/or 23 are damaged (e.g., by containing glass shards). In otherembodiments, the anti-condensate coating can be applied to any ofsurfaces 26-29 or to a surface of another pane or panel of vacuum panel20. For example, the anti-condensate coating can be applied to anoptional safety panel located adjacent to surface 26 and/or surface 29.The anti-condensate coating can be applied by spraying, adhering,laminating, or otherwise depositing the coating (e.g., using chemicalvapor deposition or any other suitable technique). In some embodiments,the anti-condensate coating is made of a self-healing material (e.g.,urethane) and is capable of healing scratches.

In some embodiments, the anti-condensate coating is anelectrically-conductive coating. To provide electricity to the coating,vacuum panel 20 may include parallel bus bars (e.g., top and bottom,left and right side, etc.). The bus bars may be spaced apart from oneanother and adhered to the electrically-conductive coating. Each bus barmay include a lead assembly or solder tab for adhering wires that are incommunication with an electrical source. In this arrangement, electriccurrent may pass through one of the lead assemblies, to a first of thebus bars, across the electrically-conductive coating to the second busbar, and through the other lead assembly. The electric current may causeheat to be generated across panes 21 and/or 23 (e.g., due to electricalresistance of the coating), which may assist in preventing condensationon panes 21 and/or 23. An exemplary bus bar system is described ingreater detail in U.S. Pat. Nos. 6,606,832, and 6,606,833, which areincorporated by reference herein for their descriptions thereof. The busbars and the electrically-conductive coating may be components of aheating element configured to apply heat to vacuum panel 20. The heatingelement may be used to prevent condensation when vacuum panel 20 isimplemented in humid environments and/or when vacuum panel 20 is used toprovide thermal insulation between spaces having relatively largetemperature differences. For example, the heating element may be usedwhen vacuum panel 20 is implemented as part of a freezer door.

In some embodiments, display case door 12 is configured to maximizevisible light transmission from inside the case to the customer, therebyimproving the ability of customers to view display items. However, it isalso desirable to minimize the transmission of non-visible light (i.e.,ultraviolet and infrared light) through vacuum panel 20 from outside toinside the case in order to improve thermal performance (e.g., byreducing radiation heat transfer) and to protect items therein. In someembodiments, an anti-reflective coating may be applied to one or both ofvacuum panes 21 and 23. The anti-reflective coating may absorb ortransmit infrared light, ultraviolet light, or any combination thereof.In some embodiments, the anti-reflective coating may absorb or transmitsome frequencies of visible light in addition to infrared and/orultraviolet light.

In some embodiments, display case door 12 may be configured to usenon-visible wavelengths of light to heat vacuum panel 20, therebyreducing or preventing condensation. For example, one or both of vacuumpanes 21 and 23 may include an ultraviolet (UV) inhibitor. A UVinhibitor may increase the shelf life of products within thetemperature-controlled storage device by preventing ultraviolet lightfrom passing through vacuum panel 20. The ultraviolet light may beabsorbed or reflected by the UV inhibitor and may be used as a source ofenergy to heat vacuum panel 20. As another example, one or more panes ofvacuum panel 20 may be treated with a low-emissivity heat-reflectivecoating to improve overall thermal resistance (e.g., by reducingradiation heat transfer) and/or to prevent external condensation.

Advantageously, vacuum panel 20 is a thermopane unit that appears as asingle pane of glass due to the minimal separation (e.g., 0.2 mm)between vacuum panes 21 and 23. The minimal separation is achieved byproviding an evacuated gap 25 between vacuum panes 21 and 23, whichcreates a thermobreak having a high thermal resistance. The thickness ofgap 25 can be precisely controlled by providing spacers 30 to maintainthe separation between panes 21 and 23.

Referring now to FIGS. 7E-7G, several drawings of a vacuum tube 40 areshown, according to an exemplary embodiment. FIG. 7E is a top view ofvacuum tube 40; FIG. 7F is a front cross-sectional view of vacuum tube40; and FIG. 7G is a perspective view of vacuum tube 40. Vacuum tube 40may be used to pump air out of gap 25 via vacuum port 34. For example,vacuum tube 40 may be inserted into vacuum port 34 and may be configuredto attach to an external vacuum pump. In some embodiments, vacuum tube40 is made of a soft copper material. In other embodiments, vacuum tube40 may be made of glass.

Vacuum tube 40 is shown as a cylindrical tube having a bore 44 extendingaxially therethrough. Vacuum tube 40 includes a radial flange 41projecting from an outer circumferential surface of vacuum tube 40 anddividing vacuum tube 40 into a first portion 42 and a second portion 43.In some embodiments, flange 41 is offset from the center of vacuum tube40 such that the axial length of first portion 42 is shorter than theaxial length of second portion 43. Vacuum tube 40 may be fused or bondedto vacuum pane 21 or 23 such that first portion 42 or second portion 42is located within vacuum port 34. In some embodiments, vacuum tube 40 isbonded to vacuum pane 21 or 23 using the same material that formsperimeter seal 32 (e.g., S-Bond solder).

Referring now to FIGS. 7H-7K, several drawings illustrating cap 33 ingreater detail are shown, according to an exemplary embodiment. FIG. 7His a top view of cap 33; FIG. 7I is a perspective view of cap 33; FIG.7J is a front view of cap 33; and FIG. 7K is a side cross-sectional viewof cap 33. Cap 33 is shown having a frustoconical shape including a topcircular surface 35, a bottom circular surface 39, and a side surface 37connecting top surface 35 and bottom surface 39. Top surface 35 andbottom surface 39 may be parallel surfaces offset from each other andconcentrically aligned. In some embodiments, top surface 35 is smallerthan bottom surface 39. Side surface 37 may be oriented at an obliqueangle (e.g., approximately 45 degrees) relative to top surface 35 andbottom surface 39.

As shown in FIG. 7K, a cylindrical bore 45 may extend partially throughcap 33. Bore 45 may have a diameter that is substantially equal to theouter diameter of vacuum tube 40 such that first portion 42 or secondportion 43 can be received in bore 45. In various embodiments, cap 33may be made of a metal (e.g., aluminum, copper, stainless steel, etc.),ceramic, glass, or other inorganic material capable of maintaining thevacuum within gap 25. Cap 33 may be bonded to vacuum tube 40, vacuumpane 21, and/or vacuum pane 23. For example, the inner surface of bore45 may be bonded to the outer surface of vacuum tube 40. Bottom surface39 may be bonded to outside surface 29 of vacuum pane 23 (as shown inFIG. 7D) or to outside surface 26 of vacuum pane 21 (e.g., forembodiments in which vacuum port 34 extends through vacuum pane 21).

Referring now to FIGS. 7L-7M, vacuum pane 23 is shown in greater detail,according to an exemplary embodiment. FIG. 7L is a front elevation viewof vacuum pane 23 and FIG. 7M is a detail view of the portion of vacuumpane 23 highlighted in FIG. 7L. Vacuum pane 23 is shown to include avacuum port 34 extending through the thickness of the glass (e.g.,between surfaces 28 and 29). Vacuum port 34 may be formed prior totempering vacuum pane 23 to avoid damage that could result from cuttinga hole in tempered glass. After vacuum port 34 is formed, vacuum pane 23may be tempered, along with vacuum pane 21.

Perimeter seal 32 is shown extending along the perimeter of vacuum pane23. As previously described, perimeter seal 32 may be applied using aprinting process. In other embodiments, perimeter seal 32 may be appliedby tinning the perimeter of vacuum pane 23 and applying perimeter seal32 to the tinned portion. Vacuum pane 21 may be the same or similar tovacuum pan 23, with the exception that vacuum pane 21 may not includevacuum port 34. In other embodiments, vacuum port 34 may be formed invacuum pane 21 (and not vacuum pane 23). One or both of vacuum panes 21and 23 may include a low-emissivity coating, an anti-condensate coating,a heat-reflective coating, a protective laminate layer, or other typesof coatings as previously described.

Referring now to FIG. 7N, a flow diagram illustrating a manufacturingprocess for vacuum panel 20 is shown, according to an exemplaryembodiment. The manufacture of vacuum panel 20 may begin with vacuumpane 23 in a non-tempered condition (stage 81). Prior to temperingvacuum pane 23, vacuum port 34 may be formed (e.g., cut, drilled, etc.)in vacuum pane 23. This allows vacuum port 34 to be formed withoutdamaging vacuum pane 33. After vacuum port 34 is formed, vacuum pane 23may be tempered, resulting in a tempered pane of glass with a vacuumport 34 extending therethrough (stage 83).

The manufacturing process may include applying perimeter seal 32 andspacers 30 (stage 85). In some embodiments, perimeter seal 32 andspacers 30 are formed using a printing process (e.g., 2D or 3D printing)or an additive manufacturing process as previously described. In otherembodiments, the outer perimeter of vacuum pane 23 may be tinned andperimeter seal 32 may be applied to the tinned portion. Perimeter seal32 may be applied to only vacuum pane 23, only vacuum pane 21, or bothvacuum pane 21 and 23 in various embodiments.

Vacuum panes 21 and 23 may be aligned in parallel and welded together(stage 87). In some embodiments, the welding process is an ultrasonicwelding process. In some embodiments, the welding process involvesheating the perimeter of vacuum panes 21 and 23 to a temperaturesufficient to melt perimeter seal 32. As previously described, perimeterseal 32 may be a low-temperature solder or other sealing material thathas a melting range significantly lower than the glass transitiontemperature of vacuum panes 21 and 23. For example, perimeter seal 32may have a melting range of approximately 220° C.-280° C., whereas theglass transition temperature of vacuum panes 21 and 23 may beapproximately 520° C.-600° C. (i.e., the glass transition temperaturefor soda lime glass). The relatively lower melting temperature ofperimeter seal 32 allows perimeter seal 32 to melt and bond to vacuumpanes 21 and 23 without heating any portion of vacuum panes 21-23 to atemperature that would remove the temper from the glass. Advantageously,this allows vacuum panes 21 and 23 to be made of tempered glass and toretain their temper throughout the manufacturing/bonding process.

After vacuum panes 21 and 23 are welded together, a vacuum may be drawnwithin gap 25 (e.g., using vacuum tube 40) and cap 33 may be applied(stage 89). Cap 33 may be fastened (e.g., attached, bonded, fixed, etc.)to the surface of vacuum pane 23 or vacuum pane 21 to cover vacuum port34 and maintain the vacuum in gap 25. Cap 33 may be bonded to vacuumtube 40, vacuum pane 21, and/or vacuum pane 23. For example, end cap 33may be bonded to outside surface 29 of vacuum pane 23 (as shown in FIG.7N) or to outside surface 26 of vacuum pane 21 (e.g., for embodiments inwhich vacuum port 34 extends through vacuum pane 21).

Referring now to FIGS. 8A and 8B, an assembled version of vacuum panel20 is shown, according to another exemplary embodiment. As shown in FIG.8B, vacuum panes 21 and 23 are positioned in parallel and offset fromeach other by the width of gap 25. The width of gap 25 (e.g., thedistance between panes 21 and 23) may be uniform or substantiallyuniform at various locations between vacuum panes 21 and 23 due to theflatness of vacuum panes 21 and 23.

Still referring to FIG. 8B, a plurality of spacers 30 are shownpositioned within gap 25. Spacers 30 may be configured to maintain theseparation between vacuum panes 21 and 23 when gap 25 is evacuated.Spacers 30 may prevent external pressure (e.g., atmospheric pressure)from causing vacuum panes 21 and 23 to flex inward when a vacuum isdrawn in gap 25. In some embodiments, spacers 30 include a plurality ofsupport pillars extending between vacuum panes 21 and 23 (e.g., betweensurfaces 27 and 28). The support pillars may be configured to provideinternal support (e.g., compression support) for vacuum panel 20 tocounter the pressure differential between atmospheric pressure outsidevacuum panes 21 and 23 and the vacuum between panes 21 and 23 (e.g., ingap 25).

As shown in FIG. 8A, spacers 30 may be arranged in a grid (e.g.,approximately 50 mm apart) between panes 21 and 23. In some embodiments,spacers 30 are separated from each other by a distance approximately tentimes the thickness of gap 25. In some embodiments, each of spacers 30has a thickness equivalent to the thickness of gap 25 (e.g.,approximately 0.2 mm). Spacers 30 may contact surfaces 27 and 28 toensure that the thickness of gap 25 is maintained. In some embodiments,spacers 30 are cylindrical or substantially cylindrical. Spacers 30 mayhave a diameter or width of approximately 0.5 mm. Spacers 30 may betransparent or semi-transparent to minimize the visibility thereof.

Still referring to FIGS. 8A and 8B, gap 25 may be sealed around aperimeter of vacuum panes 21 and 23 by perimeter seal 32. Perimeter seal32 may be, for example, a ceramic frit, glass solder or another sealingmaterial configured to bond vacuum panes 21 and 23 along a perimeterthereof and to provide an airtight seal within gap 25. In someembodiments vacuum pane 23 is smaller than vacuum pane 21. For example,the perimeter of vacuum pane 23 may be circumscribed by the perimeter ofvacuum pane 21. Perimeter seal 32 may bond with vacuum pane 23 along thetop, bottom, and side surfaces of vacuum pane 23. Perimeter seal 32 maybond with vacuum pane 21 along inside surface 27. Gap 25 may be accessedvia a vacuum port 34 extending through one of vacuum panes 21 or 23. Forexample, as shown in FIG. 8A, vacuum port 34 passes through rear vacuumpane 23 between surfaces 28 and 29. In other embodiments, vacuum port 34may pass through front vacuum pane 21 or through perimeter seal 32.Vacuum port 34 may be used to remove air from gap 25 (e.g., afterperimeter seal 32 is applied) to draw a vacuum in gap 25.

Vacuum port 34 may be capped (e.g., closed, sealed, blocked, etc.) by anend cap 36. End cap 36 may be fastened (e.g., attached, bonded, fixed,etc.) within vacuum port 34 to maintain the vacuum in gap 25. End cap 36may be sealed to vacuum pane 21 or to vacuum pane 23 by a cap seal 38.Cap seal 38 may be the same or similar to perimeter seal 32. Forexample, cap seal 38 may be a ceramic frit, glass solder, or anothersealing material configured to bond end cap 36 to one or both of vacuumpanes 21 and 23 (e.g., bonding to surface 29 or to surface 26).

Rail Assembly

Referring now to FIG. 9, vacuum panel 20 is shown with edge guards 22,according to an exemplary embodiment. Edge guards 22 may by openchannels (e.g., U-shaped or C-shaped channels) configured to fit over anedge of vacuum panel 20. Edge guards 22 may be adhered to the top edge,bottom edge, and non-hinge side edge of vacuum panel 20. For example,silicon or the like could be used for bonding. In some embodiments, edgeguards 22 may be made of a transparent or semi-transparent material tomaximize visibility through display case door 12.

Edge guards 22 may provide a sealing feature and may ensure that aperson cannot come into contact with any electrically charged surfaces.Preferably, the edge guard 22 on the non-hinged side edge of vacuumpanel 20 (e.g., on the right in FIG. 9) includes a wiper 22 a thatcooperates with a corresponding wiper 22 a on an opposite oriented door(as shown in FIG. 5) to seal the temperature-controlled storage devicewhen doors 12 are closed. In another embodiment, edge guards 22 may beomitted.

Referring now to FIGS. 10-12, vacuum panel 20 is shown secured in rail18, according to an exemplary embodiment. Rail 18 may attach to vacuumpanel 20 along the vertical length of vacuum panel 20. Rail 18 is shownto include a channel 50 having openings at the top and bottom thereof.The openings into channel 50 may be configured to receive hinge pins forhingedly connecting door 12 to frame 14. In a preferred embodiment,display case door assembly 10 includes a gravity hinge 52 at the bottomof channel 50 and an electrical hinge 54 at the top of channel 50(described in greater detail with reference to FIGS. 13-16). In otherembodiments, electrical hinge 54 may be omitted or replaced with anon-electrical hinge.

As shown in FIG. 10, rail 18 may have an “L” shaped cross-section whenviewed from the top or the bottom. The “L” shape is shown to include ahinge portion 56 and a vacuum panel receiving portion 58. Vacuum panelreceiving portion 58 may include opposing members 58 a and 58 b thatdefine a channel 74 for receiving and securing vacuum panel 20. In someembodiments, rail 18 is an aluminum extrusion into which vacuum panel 20is bonded (e.g., using an adhesive such as epoxy or polyurethane). Atape that incorporates an adhesive, such as acrylic or the like may alsobe used. In other embodiments, a mechanical clamp could be used tosecure vacuum panel 20 place. Combinations of a clamp and adhesives ortape could also be used. None of these are a limitation on the presentinvention. In other embodiments, rail 18 can be made of anothermaterial, such as stainless steel or other metal.

Gravity Hinge

Referring now to FIGS. 13-16, those skilled in the art will appreciatethe advantages of a gravity hinge, which generally includes a lowerportion and an upper portion that rotates about an oblique junction uponthe application of a rotational force. As the upper portion rotates, thetwo portions separate due to the oblique junction. The upper portion“rises” thereby storing potential energy which will cause the upperportion to “fall” or rotate back to a neutral position when therotational force is terminated. Examples of gravity hinges are shown inU.S. Pat. No. 4,631,777 to Takimoto, U.S. Pat. No. 3,733,650 to Douglasand U.S. Pat. No. 4,991,259 to Finkelstein et al, the entireties ofwhich are incorporated herein by reference.

The gravity hinge 52 of the preferred embodiment includes a lowerportion 60 and an upper 62. The lower portion 60 includes a plate 64having an axial rod 66 extending upwardly therefrom. The upper portion62 includes a collar 68 and a hinge pin 70 that are axially aligned andcooperate to define an opening 72 for receiving axial rod 66 of lowerportion 60. Lower and upper portions 60 and 62 each include a cam trackthereon (e.g., cam tracks 60 a and 62 a, respectively) that cooperate asdescribed below. To secure door 12 on gravity hinge 52, hinge pin 70 isreceived in an opening at the bottom of channel 50 and rail 18 rests oncollar 68.

In a preferred embodiment, the gravity hinge 52 includes a hold openfeature. As shown in FIG. 14, cam track 62 a on the upper portion 62includes two peaks 76 and 78, one corresponding to the door closedposition 76 and the other corresponding to the door open position 78.These peaks or detents are sized to receive the lower portion's camtrack 62 a. FIG. 17, shows gravity hinge 52 in the closed position.Preferably, closed peak 76 extends vertically higher than open peak 78.With this arrangement, when a user pushes door 12 from the open positiontoward the closed position, as a result of gravity and the potentialenergy stored when the door is in the open position, the door will fallto the closed position. FIG. 17 shows gravity hinge 52 just as the upperportion 62 is about to fall to the closed position. As shown in FIGS.13-16, peaks 76 and 78 are preferably located about 90° apart, whichallows door 12 to be held open at a position about perpendicular to theclosed position. However, open detent 78 can be defined at other anglesabout the collar 68, as desired.

Referring now to FIGS. 16-17, plate 66 is shown to include an alignmentmember 80 extending downwardly that is received into an alignmentopening 82 in frame 14. Plate 64 also has an elongated slot 84 definedtherein. To secure gravity hinge 52 to frame 14, a threaded fastener,such as a riv nut or clinch nut (not shown) extends through slot 84 andis threaded into an opening 86 in frame 14. Elongated slot 84 allowsgravity hinge 52 a degree of adjustability. This helps prevent door sagand helps keep door 12 square or plumb as desired. It will be understoodthat gravity hinge 52 can be secured to frame 14 by other methods, suchas welding, adhering, a threaded fastener with a nut, riveting, etc. Ina preferred embodiment, upper portion 62 is comprised of a molded nylonand lower portion 60 is comprised of a metal, such as die cast zinc,stainless steel or the like.

With reference to FIGS. 19-21, another embodiment of a gravity hinge 104is shown. This gravity hinge 104 is similar to the gravity hinge 52described above, except that the lower and upper portions 60 and 62 eachinclude dual or first and second cam tracks 60 a, 60 b and 62 a thereon.As shown in FIG. 21, cam tracks 62 a and 62 b on upper portion 62 eachcomprise two peaks 76 a, 76 b and 78 a, 78 b, two corresponding to thedoor closed position 76 a, 76 b and the others corresponding to the dooropen position 78 a, 78 b. These peaks or detents are sized to receivethe lower portion's cam tracks 62 a and 62 b. FIG. 19, shows gravityhinge 104 in the closed position. Preferably, closed peaks 76 a and 76 bextend vertically higher than open peaks 78 a and 78 b. With thisarrangement, when a user pushes the door from the open position towardthe closed position, as a result of gravity and the potential energystored when the door is in the open position, the door will fall to theclosed position. As shown in FIGS. 19-21, in a preferred embodiment,closed peaks 76 a and 76 b are about 180° apart. Also, open peaks 78 aand 78 b are about 180° apart. This helps distribute the weight or loadof the door and helps prevent door sag, damage, wear and tear, etc.

It will be understood by those skilled in the art that all of thecomponents of display case door assembly 10, including door 12 (e.g.,vacuum panel 20, rail 18, etc.), gravity hinges 52 or 104 and electricalhinge pin 54, among others, are all reversible and can be used on lefthinge and right hinge doors. For example, see FIG. 15, which shows thesame configuration gravity hinge 52 for left hinge and right hingedoors. In another embodiment, the components of the upper and lowerportions 60, 62 of the gravity hinges can be reversed such that theconcave portions of the cam track are on the lower portion, the convexportions of the cam track are on the upper portion and the axial rodextends from the upper portion, etc.

In some embodiments, gravity hinge 104 can be replaced with one or moretorque hinges. The torque hinges may be configured to apply a torque todoor 12 which automatically returns door 12 to a closed position. Forexample, the torque hinges may include internal springs (e.g., torsionsprings, linear springs, etc.) which store energy when door 12 is openedand apply a closing torque to door 12 (i.e., a torque which causes door12 to move toward the closed position). In some embodiments, the torquehinges are attached directly to vacuum panel 20. Examples of torquehinges which may be used in display case door assembly 10 include any ofthe torque hinges manufactured by TorqMaster International of Stamford,Conn.

Electrical Hinge Pin

With reference to FIGS. 13 and 18, as discussed above, the assemblypreferably includes an electrical or plug in hinge pin 54 at the topthereof. For example, electrical hinge pin 54 can be that taught in U.S.Pat. No. 4,671,582 (referred to herein as “the '582 patent”), titledcombined plug-in hinge pin and double ended electrical connector for ahinged appliance door, with mating receptacle and connectors, issuedJun. 9, 1987, the entirety of which is incorporated herein by reference.As shown in FIG. 18, the components identified as the combined plug-inhinge pin and double-ended electrical plug assembly 130, hinge pin part136, male contact pin members 152, and female connector assembly 190 arenumbered items 30, 36, 52, and 90 of the '582 patent.

In a preferred embodiment, there is a gap 88 between the top of rail 18.As shown in FIG. 13, gap 88 is more specifically between rail 18 andreinforcing member 90 (part of the male connection portion of electricalhinge pin 54). Gap 88 allows door 12 to travel up and down as a resultof the cam action of gravity hinge 52.

As shown in FIG. 13, electrical hinge pin 54 includes a hinge pin part136 that extends downwardly into the top opening of tunnel 50.Therefore, hinge pin part 136 and hinge pin 70 are coaxial (as a resultof both extending into tunnel 50) and allow door 12 to pivot. Hinge pinpart 136 houses insulated conductors 92 that extend out of the bottom ofhinge pin part 136 and into tunnel 50. As shown in FIG. 10, which is across section of door 12, rail 18 includes a conductor opening 94defined therein that provides communication between tunnel 50 andchannel 74. For implementations in which vacuum panel 20 is powered,power can run from a wall outlet or the like, through wiring hidden inframe 14, through electrical hinge pin 54 down wires 92 extending downtunnel 51, through the conductor opening 94, into channel 74 and tosolder tabs 96. Solder tabs 96 may connect with bus bars to providepower to an electro-conductive coating (e.g., on surface 29). In thisarrangement, all the wires necessary to provide power to theelectro-conductive coating (if any) can be hidden from view of aconsumer.

In a preferred embodiment, rail 18 also includes wire access opening 98that opens to the outside of rail 18. In this embodiment, wires 92 fromelectrical hinge pin 54 pass down tunnel 50 to opening 98, and wires 92from the bus pass down channel 74, through opening 94 to opening 98where, during assembly, electrical connections between the wires can bemade externally. Once electrical hinge pin 54 and vacuum panel 20 leadconnections are made, wires 92 are placed back into rail 18 and anaccess cover 100 is inserted in the wire access hole 98 to conceal theconnections. Access cover 100 is preferably made of plastic or the likeand includes tabs 102 that secure it within the opening 98 via a snapfit.

Configuration of Exemplary Embodiments

The construction and arrangement of the systems and methods as shown inthe various exemplary embodiments are illustrative only. Although only afew implementations of the present disclosure have been described indetail, those skilled in the art who review this disclosure will readilyappreciate that many modifications are possible (e.g., variations insizes, dimensions, structures, shapes and proportions of the variouselements, values of parameters, mounting arrangements, use of materials,colors, orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter recited.

Numerous specific details are described to provide a thoroughunderstanding of the disclosure. However, in certain instances,well-known or conventional details are not described in order to avoidobscuring the description. References to “some embodiments,” “oneembodiment,” “an exemplary embodiment,” and/or “various embodiments” inthe present disclosure can be, but not necessarily are, references tothe same embodiment and such references mean at least one of theembodiments.

Alternative language and synonyms may be used for anyone or more of theterms discussed herein. No special significance should be placed uponwhether or not a term is elaborated or discussed herein. Synonyms forcertain terms are provided. A recital of one or more synonyms does notexclude the use of other synonyms. The use of examples anywhere in thisspecification including examples of any terms discussed herein isillustrative only, and is not intended to further limit the scope andmeaning of the disclosure or of any exemplified term. Likewise, thedisclosure is not limited to various embodiments given in thisspecification.

The elements and assemblies may be constructed from any of a widevariety of materials that provide sufficient strength or durability, inany of a wide variety of colors, textures, and combinations. Further,elements shown as integrally formed may be constructed of multiple partsor elements.

As used herein, the word “exemplary” is used to mean serving as anexample, instance or illustration. Any implementation or designdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other implementations or designs. Rather,use of the word exemplary is intended to present concepts in a concretemanner. Accordingly, all such modifications are intended to be includedwithin the scope of the present disclosure. Other substitutions,modifications, changes, and omissions may be made in the design,operating conditions, and arrangement of the preferred and otherexemplary implementations without departing from the scope of theappended claims.

As used herein, the terms “approximately,” “about,” “substantially,” andsimilar terms are intended to have a broad meaning in harmony with thecommon and accepted usage by those of ordinary skill in the art to whichthe subject matter of this disclosure pertains. It should be understoodby those of skill in the art who review this disclosure that these termsare intended to allow a description of certain features described andclaimed without restricting the scope of these features to the precisenumerical ranges provided. Accordingly, these terms should beinterpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the invention as recited in theappended claims.

As used herein, the term “coupled” means the joining of two membersdirectly or indirectly to one another. Such joining may be stationary innature or moveable in nature and/or such joining may allow for the flowof fluids, electricity, electrical signals, or other types of signals orcommunication between the two members. Such joining may be achieved withthe two members or the two members and any additional intermediatemembers being integrally formed as a single unitary body with oneanother or with the two members or the two members and any additionalintermediate members being attached to one another. Such joining may bepermanent in nature or alternatively may be removable or releasable innature.

Although only a few embodiments have been described in detail in thisdisclosure, many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.). For example, the position of elements may bereversed or otherwise varied and the nature or number of discreteelements or positions may be altered or varied. Accordingly, all suchmodifications are intended to be included within the scope of thepresent disclosure. The order or sequence of any process or method stepsmay be varied or re-sequenced according to alternative embodiments.Other substitutions, modifications, changes, and omissions may be madein the design, operating conditions and arrangement of the exemplaryembodiments without departing from the scope of the present disclosure.

1.-20. (canceled)
 21. A vacuum-insulated refrigerated display case door, comprising: a hinge rail comprising a channel running along a length of the hinge rail and a hinge receiving portion defining two openings shaped to receive hinge pins for mounting the door to a refrigerated display case; a vacuum-insulated glass (VIG) panel assembly having a front surface arranged to face away from a refrigerated display case with the door mounted, and a rear surface arranged to face into the refrigerated display case with the door mounted, the VIG panel assembly comprising: two panes of tempered glass bounding a sealed evacuated space between the panes, a first edge of the VIG panel assembly disposed within the channel of the hinge rail, and a vacuum port passing through the rear surface of the VIG panel assembly, wherein the VIG panel assembly is arranged in the hinge rail such that the vacuum port is exposed to the inside of the refrigerated display case with the door mounted and the door in a closed position; and a handle secured to the front surface of the VIG panel assembly and arranged to extend away from the refrigerated display case with the door mounted.
 22. The door of claim 21, wherein the vacuum port is positioned proximate to a second edge of the VIG panel assembly, and wherein the VIG panel assembly is arranged in the hinge rail such that the second edge forms a top edge of the door with the door mounted.
 23. The door of claim 21, wherein the vacuum port is positioned proximate to a corner formed by the first edge of the VIG panel assembly and a second edge of the VIG panel assembly, and wherein the VIG panel assembly is arranged in the hinge rail such that the second edge forms a top edge of the door with the door mounted.
 24. The door of claim 21, further comprising an anti-condensate coating at the rear surface of the VIG panel assembly.
 25. The door of claim 21, further comprising edge guards coupled to each of a second edge, a third edge, and a fourth edge of the VIG panel assembly, wherein one of the edge guards comprises a wiper configured to seal the door when the door is in a closed position.
 26. The door of claim 25, wherein the edge guards are substantially transparent.
 27. The door of claim 25, wherein the edge guards are bonded to respective ones of the second, third, and fourth edges of the VIG panel assembly.
 28. The door of claim 21, wherein the VIG panel assembly comprises a plurality of spacers disposed between the panes and defining a spacing between adjacent spacers of between 20 mm and 80 mm.
 29. The door of claim 21, wherein the handle is secured to the VIG panel assembly by an adhesive bond.
 30. The door of claim 21, wherein the VIG panel assembly is arranged in the hinge rail such that the vacuum port is positioned proximate a corner formed between either the first edge and a second edge or a third edge and the second edge, wherein the second edge forms a top edge of the door.
 31. A refrigerated display case comprising: a frame; and a first vacuum-insulated door and a second vacuum-insulated door mounted to the frame, each of the first vacuum-insulated door and the second vacuum-insulated door comprising: a hinge rail comprising a channel running along a length of the hinge rail and a hinge receiving portion defining two openings shaped to receive hinge pins for mounting the door to a refrigerated display case; a vacuum-insulated glass (VIG) panel assembly having a front surface arranged to face away from a refrigerated display case with the door mounted, and a rear surface arranged to face into the refrigerated display case with the door mounted, the VIG panel assembly comprising: two panes of tempered glass bounding a sealed evacuated space between the panes, a first edge of the VIG panel assembly disposed within the channel of the hinge rail, and a vacuum port passing through the rear surface of the VIG panel assembly, wherein the VIG panel assembly is arranged in the hinge rail such that the vacuum port is exposed to the inside of the refrigerated display case with the door mounted and the door in a closed position; and a handle secured to the front surface of the VIG panel assembly and arranged to extend away from the refrigerated display case with the door mounted.
 32. The refrigerated display case of claim 31, wherein the vacuum port is positioned proximate to a second edge of the VIG panel assembly, and wherein the VIG panel assembly is arranged in the hinge rail such that the second edge forms a top edge of the door with the door mounted.
 33. The refrigerated display case of claim 31, wherein the vacuum port is positioned proximate to a corner formed by the first edge of the VIG panel assembly and a second edge of the VIG panel assembly, and wherein the VIG panel assembly is arranged in the hinge rail such that the second edge forms a top edge of the door with the door mounted.
 34. The refrigerated display case of claim 31, further comprising an anti-condensate coating at the rear surface of the VIG panel assembly.
 35. The refrigerated display case of claim 31, further comprising edge guards coupled to each of a second edge, a third edge, and a fourth edge of the VIG panel assembly, wherein one of the edge guards comprises a wiper configured to seal the door when the door is in a closed position.
 36. The refrigerated display case of claim 35, wherein the edge guards are substantially transparent.
 37. The refrigerated display case of claim 35, wherein the edge guards are bonded to respective ones of the second, third, and fourth edges of the VIG panel assembly.
 38. The refrigerated display case of claim 35, wherein the wiper of the first vacuum-insulated door cooperates with the wiper of the second vacuum-insulated door to seal the refrigerated display case when both the first vacuum-insulated door and the second vacuum-insulated door are in the closed position.
 39. The refrigerated display case of claim 31, wherein the VIG panel assembly comprises a plurality of spacers disposed between the panes and defining a spacing between adjacent spacers of between 20 mm and 80 mm.
 40. The refrigerated display case of claim 31, wherein the VIG panel assembly of the first vacuum-insulated door is arranged in the hinge rail such that the vacuum port is positioned proximate a corner formed between either the first edge and a second edge or a third edge and the second edge, wherein the second edge forms a top edge of the first vacuum-insulated door. 